Sorry, I focused on the book in my earlier reply and missed this:
Some ideas include: cutting threads, cutting gears, knurling and making small custom enclosures for electronics projects (integrated PCB bosses, front-panel holes, etc.).
With respect to cutting threads, grear, and knurling:
1) Knurling is easy compared to the other two and is not too machine dependent.
2) Threading on a good lathe can actually be enjoyable. On hobbyist lathes, it can be a nightmare. I have a Prazi MD300 lathe, and it is terrible for threading. My Smart & Brown (British, mid-1960's) is a easy. Hardinge HLVH is shear joy. You can even do internal, blind hole threads relatively easily. (I have not used a Monarch 10EE, but that should be easy too.)
3) Gear cutting in a small shop is usually done on a horizontal mill. A vertical mill can be used with the proper attachment to make it into a lightweight horizontal mill. A lathe is the wrong tool.
4) For sheet metal holes, stepped drills are today's answer for either handheld or drill press. Fly and single edge cutters (e.g., boring bars) cutters are another option with a rigid set-up -- not hand held. With a mill, one often uses a center-cutting milling cutter.
As for safety, there are two things you need to worry about. 1) You doing something stupid; and 2) A coworker doing something stupid.
You will learn quickly from your mistakes, assuming you get the chance. It is rare that a co-worker learns as quickly. Safety glasses and clamps for drill presses are the standard advice. I almost never use clamps when doing PCB and other work that self-centers. But again, I am not using a 3/4" drill in 1/2" steel. Even in that case, I will often let the work center, then clamp it. Depending on the nature of the work, safety glasses can be ordinary reading glasses, as when drilling a PCB, or more industry appropriate as when using a grinder or a wire wheel brush. The latter is extremely dangerous in my opinion as wires can/will fragment and fly at you. Some wheels are much worse than others. I have found the Dremel wheels to be particularly bad, but they are not alone. In any case, if there is one situation when I always wear safety glasses, it is when using a wire wheel.
If you also need corrective glasses, let be suggest what I have found to be comfortable -- namely a headband and shield like what is often used for gas welding, but get an untinted shield. It is comfortable and doesn't fog up as badly. In fact, that is what I usually use unless I am outdoors doing something like chainsawing.